A large nuclear exchange between great powers (and currently there are 3 great powers, the US, China and Russia) would be followed by the use of conventional military forces. E.g., The US would try to capture and hold major ports of the power or powers that attacked it because holding ports is a very effective way of denying the power the ability to deploy its own conventional forces outside its own territory and the ability to rebuild its nuclear stockpile. Military planners in the power or powers that planned the nuclear strike on the US would know that and consequently would realize that it is essential to slow down the US's recovery from the strike as long as possible.
In summary, if the US ever endures a large nuclear strike, it is very likely that Canada gets nuked, too. Canada's kicking out the US military and declaring the US to be its enemy might cause a minor reduction in intensity of the nuclear attack on Canada, but is very unlikely prevent it altogether.
Yes, Switzerland was able to avoid any attacks from the UK, the US or the USSR during WWII despite sharing a border with Germany, but that was probably near thing. Also, Switzerland was very hard for Germany to invade because of how mountainous it is; in contrast, most of the cities and infra in Southern Canada is separated from the US by nothing but plains. Also, Switzerland invests very heavily in its military capacity, e.g., every Swiss male must do military service, e.g., every bridge in Switzerland is engineered to be easy for Swiss forces to blow up.
Just a back of the napkin calculation showed how silly the idea of any conventional forces surviving a full scale nuclear war. The US had around 5K warheads on ICBMs and SLBMs at the peak of the Cold War. This doesn't even count any nuclear bombs or missiles carried by bombers. Now look at a map and count the Russian cities with a population of over 150k. In 1962 (Cuban Missile Crisis), there were roughly 100 cities in the USSR at that size threshold. In a nuclear exchange, all of them are gone. Multiple times over. And most of those cities housed military forces either in them or nearby. So those are all targeted too. Every seaport, every airport, every dam, every major bridge, all targeted. The idea was to make "the rubble bounce." After a full exchange, neither the US nor the Soviets would have had anything left for a conventional conflict, with the exception of a few units that escaped the blast radius. But there would be no transport for these units, so they'd just die of starvation and disease.
I have asserted that one of the Soviet war plans made available to western scholars in the 1990s had a massive attack with conventional forces occur right after a nuclear strike. Are you saying that I am lying or severely mistaken in my interpretation of the news reports I saw about this war plan?
Also, if they ever implemented this plan, they could evacuate their cities and military bases beforehand. You didn't address this factor.
I also disagree that the US strategic nuclear forces could have destroyed all or even the majority (e.g. 75%) of the Soviets' conventional forces even if the Soviets had no advance warning or time to disperse anything into the countryside -- partly because the forces' being dispersed was their standard and routine posture.
But the overwhelming record, both archival and from officers in the Warsaw Pact since the fall of the Berlin Wall was that nuclear weapons were always considered an essential component of attacking the West. Both tactical nukes and chemical weapons were planned for and considered integral for Soviet and Warsaw forces success.
As to your contention that the Soviet conventional forces would have survived in any coherent fashion after SIOP was initiated is wishful thinking. Fortunately, that timeline was never entered.
Do you have a source for that? Because that's pretty unbelievable action to take after a full nuclear exchange that leaves every major city and military base in ruins. I'd expect most if not all the US's force-projection power would be gone immediately after a nuclear war. Sure, maybe there'd be aircraft carriers out in the ocean, but with limited ability to resupply, they'd probably lose their effectiveness sooner than later.
One Soviet war plan that was made available to Western scholars in the 1990s anticipated this invasion of Northern Europe (with conventional forces) starting immediately after the Soviets make a large nuclear strike on Western Europe. Note that tanks crew are basically immune to nuclear fallout provided they are trained to operate in fallout. Also, fallout is not like Chernobyl: it dissipates very quickly so after 3 weeks soldiers not inside tanks will be able to operate in what were 3 weeks earlier very deadly fallout plumes. (Also, the plumes never cover the entire attacked territory, but only about half of it: its just that it is impossible to predict which half.)
This particular plan avoided any attack on Britain or France (and I presume also the US) to make it less likely that Britain and France will choose to use its nukes on the USSR, but hits West Germany, the low countries and NATO airbases in northern Italy really hard to soften them up for the invasion by tanks. In summary, the plan was to grab territory, then dare NATO to take it back or to nuke the USSR in retaliation (knowing the USSR would probably respond in kind to any nukes France, Britain or the US launch at the USSR).
I've also heard experts other than Friedman say that Soviet planners always believed that a nuclear exchange would be followed by war between conventional forces.
I heard years ago from some expert that if the US ever decided that China must be suppressed as much as possible by military means, it would be foolish to try to capture the whole country (i.e., it is too big and too populous for the US to try to do what it did to Japan at the end of WWII) so capturing and occupying its ports (which of course the Western powers held collectively for decades in the past) would be the likely military goal. I figure the same thing is true of Russia. Note that as long as it has Denmark on its side, the US would not even need to occupy St Petersburg: no ship from St Petersburg is getting into the open ocean if Denmark does not want it to. Ditto Russia's ports on the Black Sea and Turkey. I.e., Russia has geographical constraints that give it even less access to the world ocean than China has. In my mind, in any existential conflict with Russia, it would be natural for the US to try to take away what little unfettered access to the world ocean Russia does have.
> One Soviet war plan that was made available to Western scholars in the 1990s anticipated this invasion of Northern Europe (with conventional forces) starting immediately after the Soviets make a large nuclear strike on Western Europe. Note that tanks crew are basically immune to nuclear fallout provided they are trained to operate in fallout.... This particular plan avoided any attack on Britain or France (and I presume also the US) to make it less likely that Britain and France will choose to use its nukes on the USSR, but hits West Germany, the low countries and NATO airbases in northern Italy really hard to soften them up for the invasion by tanks. In summary, the plan was to grab territory, then dare NATO to take it back or to nuke the USSR in retaliation.
If the USSR nuked non-nuclear NATO, they just assumed their opponents wouldn't retaliate with nukes at all? At a minimum I'd expect the Warsaw Pact countries would have gotten nuked in retaliation. And, IIRC, NATO planners anticipated an attack along these lines, and had nukes lined up to directly target the attacking communist military formations (so those formations wouldn't just be dealing with fallout).
> I heard years ago from some expert that if the US ever decided that China must be suppressed as much as possible by military means, it would be foolish to try to capture the whole country (i.e., it is too big and too populous for the US to try to do what it did to Japan at the end of WWII) so capturing and occupying its ports (which of course the Western powers held collectively for decades in the past) would be the likely military goal.
It's a completely unrealistic goal. If China hasn't been nuked to oblivion, I don't think the US could ever dream to hold its ports against a counterattack (especially given China's rate of modernization and sheer industrial capacity). If China has been nuked to oblivion, the US would almost certainly be wrecked as well, and in no state to send over anyone to hold Chinese ports.
> (which of course the Western powers held collectively for decades in the past)
That was a loooong time ago, when China was basically at a pre-modern technology level and comparatively extremely weak. That's not the case anymore, and China is now arguably the more powerful country (in the ways that matter to such a conflict) than the US.
Contrary to what many many chatterers on the internet say, "nuked to oblivion" is not a thing. A nuclear strikes with many thousands of strategic nuclear weapons against a country as large as the US, Russia or China temporarily degrades the country's economic and military capacity, then it bounces back. It is difficult to predict how quickly it bounces back, but it will not take multiple decades.
I never claimed it is realistic for the US to hold Chinese ports in 2025. The expert I heard talk about it was talking many years ago -- 15 or 20 years ago. I figure that if it was true of China 15 or 20 years ago, it is true of Russia today.
Numerous Canadian sites, military and NORAD, were and surely are on first strike lists from the USSR and later Russia.
The largest established combined bi-national military command in the world involves a fair amount of shared risk.